1. Field of the Invention
The present invention relates to a reference voltage generating circuit. More particularly, the present invention relates to a reference voltage generating circuit for generating a reference voltage that is highly stable against variations in power supply voltage and that increases relative to increases in operating temperature.
2. Description of the Related Art
Generally, a reference voltage generating circuit should be designed to generate stable reference voltages regardless of variations in power supply voltage and operating temperature.
However, a reference voltage generating circuit for generating a reference voltage that is not affected by variations in a power supply voltage and yet increases in response to increases in operating temperatures is required for semiconductor memory devices that have been developed for application in high speed devices.
A conventional semiconductor memory device has many peripheral circuit blocks that perform operations relying on the reference voltage generated by the reference voltage generating circuit. If the reference voltage of the semiconductor memory device is constant or decreased by temperature increment, the operating speed of the peripheral circuit blocks by the reference voltage can be delayed. Hence, there is a problem in that the operating speed of the semiconductor memory device may be delayed.
According to a feature of an embodiment of the present invention, there is provided a reference voltage generating circuit capable of generating a reference voltage that increases in response to increases in operating temperature regardless of changes in the power supply voltage.
According to a feature of an embodiment of the present invention, a reference voltage generating circuit includes a start-up circuit connected between a power supply voltage and a ground voltage for generating a start-up voltage, a bias current generating circuit connected between the power supply voltage and the ground voltage for generating a bias current that increases in response to increases in temperature due to the start-up voltage, a current generator connected between the power supply voltage and a reference voltage generating terminal for generating a mirrored current of the bias current, and a load connected between the reference voltage generating terminal and the ground voltage for generating a reference voltage that increases in response to increases in temperature regardless of increases in the power supply voltage.